The former Liverpool youth player is currently on loan at League One Accrington Stanley from the Millers.
Reports suggest the BluesÂ have opened talksÂ with the centre-backâ€™s representatives and a deal could go through in January.
Ihiekwe started his senior career at Wolves but failed to make a competitive appearance during his three-year stay, spending time on loan at Cheltenham Town.
The England C-capped defender joined Tranmere Rovers in May 2017, going on to make 106 club appearances before his Rotherham switch on a free transfer.
Ihiekwe joined the Millers in May last year, featuring 26 times, and has been on loan at Accrington since August.
His loan stay the Wham Stadium expires in January.
The centre-back completed the 90 minutes when Pompey travelled to Stanley for a League One clash last month.